The Rampart police probe casts light on cases in which suspects admit to crimes they didn't commit rather than risk much longer prison terms if convicted at trial.

He could plead guilty to selling drugs he had not sold and serve eight years in prison.

Or he could risk being convicted at trial and, as a three-time loser, be sentenced to life.

Ex-felon Miguel Hernandez was offered a similarly absurd "break."

He could give up 16 months of his life by pleading guilty to possessing a weapon he had never had.

Or he could demand a trial and face the possibility of four or more years in prison.

In offering criminal defendants these kinds of Hobson's choices, prosecutors and judges did not set out to induce innocent men to plead guilty--although that is what they did. The prosecutors and judges merely accepted the word of Los Angeles police that the men were guilty.

That the police turned out to be lying--and that victims of the Rampart police scandal wound up pleading guilty to crimes they did not commit--shows the extent to which police hold people's whole worlds in their hands.

The still-unfolding scandal's scorecard: Convictions have been overturned for 10 defendants who pleaded guilty and for another who was found guilty at trial. More reversals are expected.

The main job of the criminal courts, separating the innocent from the guilty, is difficult under the best of circumstances. When the police lie, it becomes all but impossible.

Prosecutors are almost wholly dependent on police for the information they use to bring cases.

And because of a popular anti-crime crackdown in California that has lasted more than 15 years, prosecutors more than ever run the state's criminal courts.

Criminal defense lawyers these days are rarely in a position even to test in court the strength of information that the police have gathered and that prosecutors present.

Anti-crime ballot initiatives have gutted the key vehicle for such tests--preliminary hearings. Eyewitnesses for the prosecution no longer have to testify at these hearings, held to determine whether there is sufficient evidence to order an accused person to stand trial. So their recollections cannot be probed by defense counsel. Instead, police officers have been empowered to stand in for them and give their accounts secondhand.

While this restriction and others hamper the defense's ability to gauge its chances of prevailing at trial, increasingly harsh punishments created by other anti-crime initiatives raise the stakes of going to trial.

Prosecutors hold these harsh punishments over the heads of defendants as negotiating tools to get them to plead guilty at an early stage of proceedings--often before any meaningful defense investigation has taken place.

The Rampart cases stand as a reminder that this kind of efficiency has its price.

In the since-overturned Rampart cases, prosecutors and judges--most of whom are former prosecutors--did what they routinely do: They offered discounts on punishment to those who agreed to plead guilty without putting the courts to the time and expense of conducting trials.

The defendants did what defendants typically do: They took the deals. They evidently believed they would be convicted anyway if they stood trial. No one would take their word against that of the police. And courts would then punish them more harshly, saying they deserved it in part because they had not shown remorse.

The big question is: Do the police regularly lie?

In the Rampart cases, it is now alleged, they told whoppers.

Some police administrators and legal commentators believe that police often tell relatively small lies, mostly to justify unlawful searches that turn up illegal weapons or drugs. These kinds of lies typically involve claims that officers saw a defendant drop drugs on the ground when an officer actually turned them up in a search of the defendant, or, more egregiously, claims that an officer saw a defendant drop drugs that the officer cannot actually link to the defendant, because he merely saw the drugs lying near the defendant and inferred that they belonged to him.

Joseph McNamara, former chief of police in Kansas City, Mo., and San Jose, has said he believes hundreds of thousands of police officers tell those kinds of lies in court every year to convict people they are convinced are guilty and who would otherwise go free. Conservative U.S. 9th Circuit Court of Appeals Judge Alex Kozinski has called this kind of police perjury widespread and described it as "an open secret long shared by prosecutors, defense lawyers and judges."

Not everyone agrees. Los Angeles County Dist. Atty. Gil Garcetti said, "I've been a prosecutor for 31 years. I've handled . . . thousands of cases. And yes, on occasion, we've had cause to question the veracity of a police officer. . . . [But] there have been so few of those cases."

When they arise, he said, they are not tolerated. A prosecutor who suspects an officer is lying, Garcetti said, is encouraged to relay his suspicion to the officer's department. But Garcetti could cite only one case that led to a prosecution for police perjury.